What Does Pain In The Right Knee Indicate?

I am a 60 year old male and was on my feet working the docks at a regatta yesterday. about 5 hours into it I started having pain in my right knee and it got to the point last night where I could barely walk. It never swelled but kept me awake and has continued to be painful all day. I ve been icing elevating and resting all day (ibuprofen takes the edge off) and am thinking that for the time being, I should wait before making an appointment to be seen. The knee has been uncomfortable following biking, rowing in crew shells etc and I am VERY ACTIVE and lean muscled. Worried that I may have a mechanical problem... Thoughts?